The rise of electric Boats

[danstanford]

Originally Posted by blu3534

Unfortunately already electric alone brings a lot of complexity. The currents are high, installation needs to be sound. Electric (for me, atm) seems much more difficult to repair at sea if something breaks. After reading Nordkyn/ZwerfCat 'lithium-info' I'm currently a bit sceptical if LFP is really such a simple dont-think-twice swap as I have thought.

With a hybrid one has redundant propulsion (in addition to the range).

I'm not sure if a portable generator is such a good idea. Efficiency drops, there is dangerous gas on board. Are portable generators robust when there is strong wind? If one goes electric then why not just accept that on long passages one has to wait if there is no wind? And shoulder the somewhat increased risk to end on a lee shore?

Though I would absolutely rather have a built-in diesel generator, a portable one on deck does just fine especially considering that in my use case it is one day out of 99 where that might be needed. When it is needed the conerns you note above are much less an issue than waiting till you can sail in. In my case the limiting factor is the battery charger (which is very convenient since I can plug the portable genny into the shore power plug) which cannot pass enough current onto the batteries to run the motor at full capacity.

[valhalla360]

Originally Posted by goboatingnow

Bio fuels are an environmental disaster , responsible for destruction of virgin forest etc

Corn ethonal in the US is a joke.

Repurposing used cooking oil makes a lot of sense.

[newhaul]

Originally Posted by valhalla360

Corn ethonal in the US is a joke.

Repurposing used cooking oil makes a lot of sense.

Corn ethanol is not a joke it is a multi billion dollar a year business. It is about useless ( except in E85 ) after all the original Ford model A was designed and built to run ethanol.
The problem with modern engines and ethanol is rubber based hoses and gaskets. Change it all out to neoprene and increase the fuel by about 25% to 30%.

Used cooking oil becomes bio diesel

[250224]

Originally Posted by danstanford

Though I would absolutely rather have a built-in diesel generator, a portable one on deck does just fine especially considering that in my use case it is one day out of 99 where that might be needed. When it is needed the conerns you note above are much less an issue than waiting till you can sail in. In my case the limiting factor is the battery charger (which is very convenient since I can plug the portable genny into the shore power plug) which cannot pass enough current onto the batteries to run the motor at full capacity.

Thank you for the feedback!

[newhaul]

Yep electric sounds great just wait for wind and sail instead of motoring . Until rigging fails and storms are brewing .

[Emoyeni]

Originally Posted by newhaul

Yep electric sounds great just wait for wind and sail instead of motoring . Until rigging fails and storms are brewing .

I agree that running out of battery when rigging fails would be a potentially bad situation. And if I had a working diesel on my boat, I wouldn’t be reading this thread. But as someone with a gas engine in their boat, I wonder if the sum of electric engine disasters iis more common or are exploding engine bays and other gas problems. Furthermore, are the rate of engine exhaust related health maladies significant to factor into the equation?

[newhaul]

Originally Posted by Emoyeni

I agree that running out of battery when rigging fails would be a potentially bad situation. And if I had a working diesel on my boat, I wouldn’t be reading this thread. But as someone with a gas engine in their boat, I wonder if the sum of electric engine disasters iis more common or are exploding engine bays and other gas problems. Furthermore, are the rate of engine exhaust related health maladies significant to factor into the equation?

When proper procedures are followed there have to my knowledge been 0 (none)
Engine fires caused by the fuel. If you have a good running engine . Imo wait to make any changes . You never know what the technology will be like or priced at in 3 years . Let alone 10 when your engine is still going strong.

[Dockhead]

Originally Posted by Adelie

Hydrogen looks very good which is why folks keep working on it but the reality is that it will never overcome problems with storage and it’s logistics tail.

Storage: long term storage involves compressing the gas to 3000psi which takes energy (5% or so of the energy in the fuel) and requires heavy tanks.

Hydrogen (3000psi): 1.8MJ/L &146MJ/kg
Gasoline/petrol: 35MJ/L& 46MJ/kg
Diesel: 39MJ/L & 45MH/kg
LiFePO (18650): 2.3MJ/L & 0.85MJ/kg

19l tank will hold 1.3kg hydrogen at 200bar.
Tank weighs about 20kg so specific energy including tank is about 9.3 MJ/kg. Actually it is slightly worse than that because you need to account for the weight and volume of the fuel cell if you are comparing to a battery. At best hydrogen including tank and cell has 7x or so the specific energy of LiFePo batteries and has about half the energy density.

https://www.nrel.gov/docs/gen/fy08/43061.pdf

https://www.skai.co/hydrogen-details

Hydrogen is great on a per kg basis but is pretty bad for volume compared to batteries. At the very best it breaks even with gas or diesel if all parts of each system are considered.

In the logistical tail there is an energy penalty to creating the hydrogen from water, and then also to compress it. There is no infrastructure for creating, compressing, storing or distribution of hydrogen so there would be a huge price in creating this infrastructure ashore, a significant fraction of $1T.

What about foregoing to shoreside infrastructure and creating and pressurizing the hydrogen aboard? Possible but then there are increased space and weight demands aboard and the whole system is significantly less efficient than LiFePo and maybe even than LA batteries. That means more solar panels for a given amount of stored energy.

There are other methods of hydrogen storage such as as hydrides, but those technologies are relatively immature so it will be decades before any of the become viable at scale.

https://www.energy.gov/eere/fuelcells/hydrogen-storage

Better than hydrogen would be electro-fuels.
Such as various forms of ammonia or even gasoline or diesel.
Ammonia is one of the most produced chemicals in the world and the technology is very mature though low or no carbon processes are currently rather expensive. Ammonia can then be used as a fuel for an ICE though it needs some other fuels to promote ignition. It can be made from air, water and electricity.
Diesel and gasoline/petrol/butanol can also be made from Air, water and electricity using the Fischer-Tropisch process. The technologies are all reasonably mature but have not been integrated or scaled up so the economics are not yet apparent.

Wow, this is a great analysis! My hat is off to you! This is a much deeper analysis than mine; I defer. Elecrofuels it is. Thank you, I learned a lot from this post.

[harlem24]

Electrofuel have the problem, that they need even more energy to be produced and are used in very inefficient ICE vehicles.
From an efficiency standpoint PtL is the worst thing you can do.
Batteries and electric motors are far better.

[Dockhead]

Originally Posted by harlem24

Electrofuel have the problem, that they need even more energy to be produced and are used in very inefficient ICE vehicles.
From an efficiency standpoint PtL is the worst thing you can do.
Batteries and electric motors are far better.

Not when power density matters.


Batteries and electric motors might be ok in cars which never get that far from a supercharger, but not in aircraft, or vessels.

[valhalla360]

Originally Posted by newhaul

Corn ethanol is not a joke it is a multi billion dollar a year business. It is about useless ( except in E85 ) after all the original Ford model A was designed and built to run ethanol.
The problem with modern engines and ethanol is rubber based hoses and gaskets. Change it all out to neoprene and increase the fuel by about 25% to 30%.

Used cooking oil becomes bio diesel

Both are biofuels. (note I was specific about corn based and waste oil based...there are other sources for each)

The joke about corn ethanol is not the fuel itself but the wasteful process that produces it. Modern engines have no issue using it.

[harlem24]

Originally Posted by Dockhead

Not when power density matters.


Batteries and electric motors might be ok in cars which never get that far from a supercharger, but not in aircraft, or vessels.

Where are you getting the energy from?
It does not come from thin air.
Atm there is a limited supply of renewables...
And from the look of it, for years to come.

[newhaul]

Originally Posted by Dockhead

Wow, this is a great analysis! My hat is off to you! This is a much deeper analysis than mine; I defer. Elecrofuels it is. Thank you, I learned a lot from this post.

Thing is they don't use highly compressed hydrogen they produce it daily using the excess solar on board and use it nightly to produce power

https://www.cnet.com/news/this-boat-...from-seawater/

My question would be where do you sit on the deck?

[harlem24]

You can, the panels are walk-on semi rigid.
But there is a huge lounge aft under the "bimini".
They do store the hydrogen:
https://www.energy-observer.org/reso...drogen-storage
63kg in high pressure composite tanks.
Nothing I would like to have on a plesure vessel...

[danstanford]

At least with the Democrat-Republican debate where so many seem to be at the poles without evidence, I can say at least they have some skin in the game. I cannot understand why so many seem dead set against electric propulsion as an option. If it is fear that someone will create public policy forcing you to convert, I am of the opinion that you are safe until there isn't enough diesel for you to get any which makes the debate moot.
Please chime in with suggestions or criticisms that you haven't heard before in the thread and I will respectfully do the same. If all you want to do is bash the idea as not feasible because it is not perfect for some applications, I don't think you are adding to the discussion but rather detracting from the discourse.
Sincerely, Dan